srcds_run is a shell script that cd's to its own dirname before exec'ing
srcds_linux, so WorkingDirectory has no effect — the binary's path is what
determines where the engine reads gameinfo.txt and addons from. Pointing
at installation/srcds_run resolved everything against the lower layer, so
overlay-provided Metamod/SourceMod plugins and cfgs (zonemod, confogl)
never loaded. Switch to runtime/%i/merged/srcds_run so the engine sees
the merged tree.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Symmetric with the earlier mount cleanup (commits 519567e..a982995). Until
now, the unit's ExecStartPre handled mount but the Python side still drove
unmount: stop_instance and _purge_instance both called _mounter.unmount,
which wrapped sudo + the helper. Two code paths for two halves of the
same lifecycle.
Move unmount into the unit:
- ExecStopPost=+/usr/local/libexec/left4me/left4me-overlay umount %i
(ExecStopPost, not ExecStop, so it runs after the cgroup is cleared;
ExecStop runs while srcds is alive and would EBUSY the umount syscall.)
- Helper's umount verb is now idempotent (mirrors mount): if merged
isn't a mount point, return early. PRINT_ONLY mode bypasses both
short-circuits so the unit tests still exercise the full nsenter argv.
Drop the dead Python machinery:
- _mounter.unmount(...) calls in stop_instance and _purge_instance
- _mounter global + KernelOverlayFSMounter import
- The whole l4d2host/fs/ package (OverlayMounter ABC + KernelOverlayFSMounter
class) — no production callers, just self-tests
- l4d2host/tests/test_kernel_overlayfs.py
- test_stop_succeeds_when_unmount_fails / test_delete_succeeds_when_unmount_fails
(tested Python-side unmount-failure tolerance that no longer exists)
- The l4d2host.fs.kernel_overlayfs.run_command monkeypatches in lifecycle tests
After this, the only thing start_instance does beyond cfg-staging is ask
systemd to enable+start the unit. stop/delete/reset only ask systemd to
disable; the overlay lifecycle lives entirely in the unit file.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
systemd 230+ moved StartLimitBurst= and StartLimitIntervalSec= from
[Service] into [Unit] (with the rename from StartLimitInterval=). Putting
them in [Service] makes systemd silently ignore them with a warning to
journalctl: "Unknown key 'StartLimitIntervalSec' in section [Service],
ignoring." — meaning the restart-loop cap I claimed in commit 519567e
wasn't actually applied.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
The unit has NoNewPrivileges=true (security hardening for srcds), which
blocks sudo's setuid escalation. The previous sudo'd ExecStartPre failed
on every start with "sudo: the 'no new privileges' switch is set, which
prevents sudo from running as root" -> Restart=on-failure loop.
systemd's `+` prefix runs the Exec command as PID 1 (root, no sandbox),
bypassing User=/Group=/NoNewPrivileges=. Equivalent privilege scope to
the sudoers rule the web app already uses for the same helper, just
without the sudo middleman.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Before this change there were two callers of left4me-overlay mount:
the web app's start_instance (Python, in-process) and the unit's
ExecStartPre (shell, via sudo). The duplication invited divergence; the
helper's recently-added idempotency made both paths technically work
but at the cost of a "first wins" race and dead-code retry logic in
start_instance.
Drop the in-process _mounter.mount() call from start_instance. The web
app now only stages cfg files (which still must happen on the host
filesystem before mount, to avoid overlayfs copy-up changing ownership),
then asks systemd to enable+start the unit; the unit's ExecStartPre
does the mount.
Removed:
- os.path.ismount(merged) refusal in start_instance and its test
(test_start_refuses_to_double_mount). The race the check guarded
against is now handled by the helper's idempotency.
- _load_instance_env helper and the `os` import (both became dead).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
systemd applies WorkingDirectory= to every Exec line including ExecStartPre.
With the merged dir not yet existing at boot time (the volatile overlay
mount has been wiped), the chdir into runtime/%i/merged/left4dead2 fails
with status=200/CHDIR before ExecStartPre can run the mount helper.
The `-` prefix makes chdir failure non-fatal: ExecStartPre runs in the
unit's home (cwd doesn't matter for the mount helper); ExecStart re-applies
WorkingDirectory once the mount has landed and chdirs successfully.
Companion to commit 519567e (which added the ExecStartPre mount + helper
idempotency but didn't account for the WorkingDirectory ordering).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
The lifecycle change to systemctl enable --now (commit 8552c55) made
units auto-start at boot. But the kernel-overlayfs mount is volatile
(reboot kills it), and the web app's start_instance only re-mounts in
response to a UI click. Result: at boot, systemd starts the unit, finds
empty merged/, CHDIR fails, Restart=on-failure spins forever (counter
hit 65 on ckn before this fix landed).
Fix:
- Unit gets `ExecStartPre=/usr/bin/sudo -n .../left4me-overlay mount %i`
so the overlay is established before the main process starts.
- Helper is now idempotent: if merged is already a mount point, exit 0.
Required because Restart=on-failure re-runs ExecStartPre on each
cycle, and the web-app's start_instance also calls the helper, so
both paths would otherwise collide on "already mounted".
- StartLimitBurst=5 + StartLimitIntervalSec=60s caps the restart loop
instead of letting it spin indefinitely on a fundamental failure.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
